Merge of r4985, r4986, r4987, r4988, r4989, r5002: access_log gzip.

*) Access log: fixed redundant buffer reallocation.  Previously a new
   buffer was allocated for every "access_log" directive with the same
   file path and "buffer=" parameters, while only one buffer per file
   is used.

*) Reopening log files code moved to a separate function.  The code
   refactored in a way to call custom handler that can do appropriate
   cleanup work (if any), like flushing buffers, finishing compress
   streams, finalizing connections to log daemon, etc..

*) Access log: the "flush" parameter of the "access_log" directive.

*) Configure: added the NGX_ZLIB define.  This was introduced for
   conditional compilation of the code that requires the zlib library.

*) Access log: the "gzip" parameter of the "access_log" directive.
   Note: this requires zlib version 1.2.0.4 or above to work.

*) The data pointer in ngx_open_file_t objects must be initialized.
   Uninitialized pointer may result in arbitrary segfaults if access_log
   is used without buffer and without variables in file path.
   Patch by Tatsuhiko Kubo (ticket #268).

1 files changed, 2 insertions, 19 deletions

diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index e5dad4607..dc4dc8993 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -1115,7 +1115,6 @@ ngx_test_lockfile(u_char *file, ngx_log_t *log)
 void
 ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user)
 {
-    ssize_t           n, len;
     ngx_fd_t          fd;
     ngx_uint_t        i;
     ngx_list_part_t  *part;
@@ -1139,24 +1138,8 @@ ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user)
             continue;
         }
 
-        len = file[i].pos - file[i].buffer;
-
-        if (file[i].buffer && len != 0) {
-
-            n = ngx_write_fd(file[i].fd, file[i].buffer, len);
-
-            if (n == -1) {
-                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
-                              ngx_write_fd_n " to \"%s\" failed",
-                              file[i].name.data);
-
-            } else if (n != len) {
-                ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
-                          ngx_write_fd_n " to \"%s\" was incomplete: %z of %uz",
-                          file[i].name.data, n, len);
-            }
-
-            file[i].pos = file[i].buffer;
+        if (file[i].flush) {
+            file[i].flush(&file[i], cycle->log);
         }
 
         fd = ngx_open_file(file[i].name.data, NGX_FILE_APPEND,